Dental matrix-retainer.



No. 792,438. PATENTED JUNE 13, 1905. W. W. MINGH.

\ DENTAL MATRIX RETAINER.

APPLIOAT-ION FI'LED 00T.15, 1904.

mihuzoom WILLIAM WV. MINOH, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO UNITED STATES Patented June 13, 1905.

PATENT OFFICE.

JAMES WV. IVORY, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL MATRIX-RETAINER.

SPECIFICATION forming part of Letters Patent No. 792,438, dated June 13, 1905.

Application filed October 15, 1904. Serial No. 228.578.

To all whom it may concern:

Be it known that I, WILLIAM W. MINOH, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented anew and useful Dental Matrix-Retainer, of which the following is a specification. A

My invention consists of an implement for retaining a dental matrix during application and service, the same being provided with novel means for opening and closing the jaws of the implement that carry said matrix. as will be pointed out in the claims.

Figure 1 represents a perspective view of a dental matrix-retainer embodying my invention. Fig. 2 represents a longitudinal section on line w m, Fig. 3. Fig. 3 represents a plan view thereof.

Similar letters of reference indicate corresponding parts in the figures.

Referring to the drawings, A designates jaws, which are continuous of or connected with the levers B, the latter being mounted by the pivot O on the plate D.

of the limbs and ride thereupon in the movement of said nut G, so as in one direction to spread said limbs and thus close the jaws A,

and in the other direction to permit said limbs to approach each other and thus open said jaws, the latter action being occasioned by the coil-spring J, which in the present case bears outwardly against the portions of the levers B forward of their axes, said spring being secured to said portions by means of the teats K, which are formed on said portions and enter the ends of said spring. It will also be noticed that the said spring is directly connected with said levers immediately in front of the plate D and does not project materially forward of the connecting-teats K, thus avoiding the projection of said spring into the space of the device forward of the levers, thereby leaving said space entirely unobstructed. It

will also be seen that the conical head H contacts directly with the inner sides of the limbs F of the levers B, thus causing a quick action on said levers, while simplifying the construction of the device, said head being also integral with the nut Gr. On the ends of the jaws are the shouldered points L, which are adapted to enter either of the openings M in the opposite ends of the matrix N, whereby the latter will be retained on the implement, as well known in the art.

The head H is a continuity of the nut G, and the latter is set out from the limbs F, so as to entirely clear the same and form a convenient handle for the rotation of said head and the consequent proper movement of the levers B.

The limbs F constitute the handle of the device, and by the use of. the same the adjustment of the head H will not be disturbed.

The operation is as follows: The jaws being properly separated or opened have the matrix applied to the points L thereof, as shown in Fig. 1, when the implement may be manipulated to apply the matrix to the place of service. The nut G is now rotated, whereby the tapering or conical head H is advanced against the limbs F of the levers B, when, owing to its wedging action, it spreads apart said limbs and causes the closing of the jaws A, whereby the matrix will be contracted to the required extent. \Vhen the matrix is to be removed, the nut G is rotated in reverse direction, whereby the head H moves outwardly with the same, so as to relieve the limbsFof the pressure of said head, the spring J then causing the jaws to separate and the matrix to expand, when the removal of the latter from the tooth will be readily effected. In order to apply the matrix to the tooth to the best advantage without interference of the plate D, nut and head G H, and the limbs F, the rear portions of the jaws are turned upwardly to the place of junction with the levers B, forming the elbows P, the advantages of which are evident, as most plainly seen on reference to Fig. 2.

Various changes may be made in the de-- tails of construction shown without departing for said levers, means for closing said jaws consisting of a non-rotatable screw which is secured to said bearing and a rotatable head of tapering form fitted on said screw and adapted to engage with the adjacent limbs of said levers, and means for opening said jaws consisting of a spring forward of said bearing, said jaws having devices for connecting the ends of the spring therewith.

WILLIAM W. MINCH.

Witnesses:

JOHN A. VVIEDERSHEIM, WM. (JANER WIEDERSEIM. 

